In view of the direct measurement difficulties of load swing angle of tower crane under some working conditions, obvious chattering of the system sliding mode controller and complicated adjustment of controller parameters, an adaptive sliding mode control method for tower crane based on improved fruit fly optimization algorithm was proposed. Firstly, based on the Lagrange equation, the dynamics model of the tower crane single pendulum system was obtained. Then, a linear extended state observer was designed to observe the load swing state of tower crane, and the observation results were fed back to the adaptive sliding mode controller. When constructing sliding mode surface, the hyperbolic tangent function was used instead of the common symbol function to increase its continuity and reduce chattering. Finally, the optimization strategy and search radius of the fruit fly optimization algorithm were improved, and the parameters of the adaptive sliding mode controller were optimized. The results showed that the designed linear extended state observer could track and observe the load swing angle of the tower crane with fast convergence speed and tracking error less than 1.3%. The adaptive sliding mode controller optimized by the improved fruit fly optimization algorithm not only had a good suppression effect on the load swing of tower crane, but also had strong anti-interference and robustness. The proposed control method can effectively avoid safety hazards caused by tower crane load swing while achieving precise positioning, ensuring the safety of workers and the smooth progress of the project.

The control system of aerial fire fighting vehicles is complex, and the operation of the entire vehicle requires multiple operators to cooperate at multiple operating positions, with high requirements for the technical level of operators. Therefore, a control system of aerial fire fighting vehicle with voice control function was proposed. On the basis of the original control system of the aerial fire fighting vehicle, automatic control function, voice control function and voice broadcast function were added to replace the conventional handle and button operation mode. Among them, the voice control function was to recognize specific voice commands from operators through voice control module and sent them to the PLC (programmable logic controller) through the CAN (controller area network) bus, and then the PLC automatically controlled the action of the fire fighting vehicle based on the voice commands and the status of the fire fighting vehicle. When the status of the fire fighting vehicle changed or malfunctioned, the PLC sent voice commands to the voice broadcast module, which played the voice based on the pre-stored voice information for operators to receive important information. The test results showed that the designed aerial fire fighting vehicle control system was feasible, which could effectively reduce the operation difficulty and improve the operation efficiency. The new control system can be quickly extended to other types of fire fighting vehicles and related construction machinery products, which has high application value.

In order to protect the RFID (radio frequency identification) antenna from oxidation and corrosion due to contact with the external environment, and to improve the anti-counterfeiting, integrity and aesthetics of the product, it is necessary to place the RFID antenna on the surface of the product structure or inside the product. In order to rapidly manufacture these products, a multi-material 3D printer integrating fused deposition modeling (FDM) and direct ink writing (DIW) 3D printing technologies was built, with a printable area of 220 mm×190 mm. The influence of antenna structure and substrate structure on the radiation performance of RFID antennas was analyzed by ANSYS HFSS simulation software. Then, four types of RFID antennas were selected as 3D printing objects, and conductive silver paste and polylactic acid (PLA) were used as printing materials for the antenna and substrate, respectively. The measured and simulated curves of the return loss of the antenna print were compared. The results showed that the resonant frequencies of the four types of RFID antennas had shifted approximately 185 MHz in the low-frequency direction relative to their design frequency of 915 MHz. Based on the measurement results of the return loss of antenna prints, the antenna model was further optimized and an embedded RFID antenna with a substrate thickness of 3 mm and an antenna arm length of 55 mm was printed, which met the design requirements of resonant frequency of 915 MHz and bandwidth greater than 150 MHz at ?10 dB. The research results verify the feasibility of integrated printing of RFID antennas and product bodies by using multi-material 3D printing technology and provide a reference for the rapid manufacturing of RFID antennas. This process has broad application prospects.

Aiming at the problem that the working gap magnetic field intensity distributes unevenly along the radial direction of the brake disc and the working gap magnetic field intensity far from the coil area is small, a multipole disc-type magnetorheological (MR) brake is proposed and designed. Firstly, the basic structure and working principle of the multipole disc-type MR brake were elaborated and the magnetic circuit modeling of the MR brake was completed, and then a mathematical model of its braking torque was established. Then, based on finite element simulation software, the magnetic field simulation analysis for the multipole disc-type MR brake was carried out. Finally, taking the torque density as an optimization objective, the structural optimization design of the multipole disc-type MR brake was completed by BOBYQA (bound optimization by quadratic approximation) algorithm within the gradient free optimization algorithm. The results showed that the external gap magnetic induction intensity of the designed MR brake was 0.681?0.760 T; the magnetic induction intensity at the internal gap of 0?<5 mm was 0.114?0.349 T, and the magnetic induction intensity at the internal gap of 5?65 mm was 0.362?0.498 T; the two magnetic fields generated by the inner and outer coils could be superimposed in the MR fluid gap, which improved the braking torque. Compared to before optimization, when the current of all inner and outer coils was 1 A, the braking torque increased by 15.2% and the torque density increased by 14.3% of the optimized MR brake. The multipole disc-type MR brake can provide a reference for the development of high torque density MR transmission technology.

The point cloud data obtained by conventional 3D point cloud information map modeling method for coal mine tunnels is large and complex, with a large amount of computation. Therefore, a 3D scanning system and a spatial modeling method for excavation tunnel based on laser scanning and 3D grid map were proposed. The 3D grid map of the tunnel space was formed through mapping point cloud data to a 3D grid and dividing the tunnel space into a finite number of grids, and the map was divided into multiple functional areas. By converting the 3D scanning lidar coordinate system to the tunnel coordinate system, the point cloud data obtained by lidar was converted into the outer contour data of the tunnel, in order to analyze the over excavation and under excavation errors of the cutting of the roadheader. The experiment showed that with a 3D grid edge length of 10 cm, when the grid map obtained by the cutting formed tunnel 3D grid map modeling method guided the automatic cutting operation of the roadheader, the data processing load could be reduced by 84.7% compared with the conventional point cloud map, which greatly reduced the burden of the cutting control system processor. The research results provide a basis for the design and application of an autonomous cutting operation system of roadheader based on lidar 3D scanning.

With the gradual shift of oil and gas exploration to deep, ultra-deep and complex rock formations, the existing mechanical drill bits have the problems of low rock breaking efficiency and high operating cost. Therefore, a new type of laser-PDC (polycrystalline diamond compact) drill bit was proposed to achieve efficient rock-breaking and energy-saving and cost-reducing. Using finite element method and based on the HJC (Holmquist-Johnson-Cook) constitutive model of rock, a nonlinear dynamic model of laser-PDC drill bit joint rock-breaking was established, and simulation research on laser-PDC drill bit joint rock-breaking was conducted. The simulation results showed that the radiation effect of laser generated higher temperature and greater prestress in the radiated area of rock surface, which in turn formed interpenetrating damage zones on the rock surface, reduced the strength of the rock, and was more conducive to cutting teeth to break the rock; compared with non-laser single PDC drill bit, laser-PDC drill bit experienced a 24.8% reduction in anti-torque during rock breaking, a 10.5% reduction in axial acceleration fluctuation, an increase in drilling displacement of 8.67 mm, and an increase in drilling speed of 112.79%. A laser-mechanical joint rock-breaking experimental bench was built to conduct laser-PDC drill bit joint rock-breaking experiment. The experimental results showed that laser-PDC drill bit joint rock-breaking had better drilling stability and continuity, greatly improving the rock-breaking efficiency. The research results can provide theoretical and technical support for the development and application of laser-mechanical rock-breaking technology.

Multi-functional small robots have broad application prospects. To meet different operational requirements, a small land-air deformable amphibious robot was designed, which could achieve efficient ground movement and avoid obstacles through takeoff flight. The robot adopted a dual-mode design, in which the ground mode adopted a two-wheel drive motion design, and the airplane mode adopted a four-rotor flight design. The switching between the two modes was realized through the support and extension of the robot tilting mechanism. In order to verify the motion performance of the robot, the whole robot model was established by SolidWorks software, the kinematics modeling for the robot was carried out, and the kinematics equation of the robot mode switching process was derived. Then, the robot servo output was simulated by MATLAB and the robot prototype mode switching experiment was carried out. The simulation results of the output torque were basically consistent with the measured results, with a range of 0-250 N·cm. Finally, the robot prototype was used to conduct ground movement and air flight tests, and its motion process was analyzed to verify the stability of the land-air motion and mode switching of the robot. The research results verify the effectiveness of the designed robot, and it has a long endurance, which can provide a reference for the design of land-air amphibious robots.

In order to solve the problems of poor wall adaptability and low movement flexibility of wall-climbing robots, the shortcomings of the existing magnetic adsorption mechanism of wall-climbing robots were analyzed. Taking a wheeled wall-climbing robot as research object, a wall adaptive pendulous magnetic adsorption mechanism was designed based on the functional requirements of wall-climbing robots. A comparative analysis was conducted between the pendulous magnetic adsorption mechanism and the traditional magnetic adsorption wheel by Ansoft software. In order to further reduce the mass of the magnetic adsorption mechanism and improve its adsorption reliability, based on the goal of high magnetic energy utilization, SNLP (sequential non-linear programming) algorithm was used to optimize the structural parameters of the pendulous magnetic adsorption mechanism. After optimization, the adsorption force of the magnetic adsorption mechanism was increased by 25.52%. A prototype of pendulous magnetic adsorption wheel was developed and the adsorption force testing experiment and demagnetization experiment were conducted. Motion performance testing experiment was carried after installing the pendulous magnetic adsorption wheel on a wall-climbing robot to verify the rationality of the optimization results of the structural parameters of the magnetic adsorption mechanism and the practicality of the structural design. The research results provide a reference for improving the working performance of wall-climbing robots.

In order to achieve the structural compactness and lightweight design of pole-climbing robots, and overcome the difficulty of vertical pole movement, the weight reduction can be realized by reducing the thickness of parts. However, it can cause local stress concentration, resulting in insufficient stiffness of robot structure. Therefore, starting from the morphology of inchworms, the SIMP (solid isotropic material with penalization) variable density topology optimization design was carried out for the main structure of the pole-climbing robot, realizing the lightweight design of the robot while ensuring its overall performance. Firstly, the main components such as the gripper and T-joint of the pole-climbing robot were selected as the objects, and three motion gaits were dynamically simulated by ADAMS simulation software to simulate the load changes caused by the three motion gaits under extreme working conditions. Then, the boundary conditions were set based on information such as extreme working condition loads. The Topology Optimization module in ANSYS Workbench software was used to perform SIMP variable density topology optimization on the pole-climbing robot to remove the redundant materials that were slightly affected by loads from the robot structure. The optimized robot model was reconstructed and compared with before optimization. The results showed that while the overall weight of the pole-climbing robot was reduced by 7.6% (from 13.60 kg to 12.57 kg), the comprehensive performance of the gripper and T-joint with larger force was improved. The experimental results of energy consumption test showed that the operating energy consumption of the optimized pole-climbing robot decreased by 7.0% compared with before optimization. The proposed SIMP variable density topology optimization method has a high reference value in the structural design of biomimetic pole-climbing robots.

In order to achieve the dredging of urban underground pipelines with complex layout, a tracked pipeline dredging robot based on parallel mechanism was proposed. Adopting a folding and posture adjustment walking device to reduce the robot's volume, and using a working device based 3-US parallel mechanism to increase the robot's workspace; a robot workspace algorithm was written, and the working range and motion trajectory of the walking device and working device were obtained by simulation through MATLAB software; the motion states of the robot were simulated by ADAMS software, and its driving characteristic parameters were analyzed. The variation rules of driving force and driving torque of the walking device under different motion states were obtained, as well as the driving torque of the working device when transitioning between extreme positions in different directions. Simulation study showed the stability of the walking device during folding and posture adjustment, as well as the flexibility of the working device in transitioning between various dredging limit positions. The research results have guiding significance for the development and application of pipeline dredging robot with diameter adjustment.

In order to design a passive lower limb exoskeleton with good assisting effect, an optimal design method of lower limb exoskeleton was proposed based on the analysis of the motion and mechanical characteristics of human walking and the mechanical performance of the relevant major muscle groups. Through the human walking experiment, the kinematics information and plantar reaction force were obtained to drive the simulation of Anybody, and the mechanical data of lower limb muscles during walking were obtained. With the help of Hill muscle model, a simplified model of muscle?tendon?bone of hip joint in the sagittal plane of the human body was established, and a virtual torsion spring was added to simulate the role of exoskeleton, forming an integrated model of human body and exoskeleton. On this basis, the human-computer interaction force and the muscle activation of the wearer were quantitatively analyzed when wearing the assisted exoskeleton. The calculation models of muscle activation degree and metabolizable energy with torsion spring stiffness as variable were established, and the stiffness of virtual torsion spring was optimized by particle swarm optimization to obtain the optimal value with the goal of minimum metabolizable energy. Based on this, the design scheme of hip joint assisted exoskeleton mechanism was proposed, and the difference between the auxiliary torque of the mechanism and the virtual torsion spring torque was minimized as the goal to optimize, and the optimal values of the tension spring stiffness and the size of each connecting rod were obtained as the design parameters of the exoskeleton mechanism. At the same time, the prototype of hip joint assisted exoskeleton was made and the experiment of assisted walking was carried out. The results showed that the metabolic energy of human body was significantly reduced when wearing the assisted exoskeleton. The research method can provide reference for the design and analysis of other lower limb exoskeletons.

Cracks at the interface between the weld in the cladding panel of spent fuel pool of a nuclear power plant and the base material can seriously affect the operational safety of the equipment. Considering the true characteristics of weld, alternating current field measurement (ACFM) technology was proposed to detect weld crack to improve the sensitivity of crack detection. Firstly, a weld crack detection model was established by COMSOL software, and the magnetic field characteristic signals in the weld crack area were analyzed; secondly, an artificial crack that was consistent with the numerical simulation was preset at the interface between the experimental specimen weld and the base material, and then the weld crack ACFM experiment was carried out; finally, a weld crack detection system was developed and its performance testing was conducted. The simulation, experiment and testing results indicated that the ACFM method could effectively identify crack parallel to the weld direction at the interface between the weld and the base metal, but could not identify crack perpendicular to the weld direction; the deviation of crack detection length obtained through the testing of the weld crack detection system was smaller than that obtained through the probe detection experiment, but the two were relatively close, proving the rationality of the design of the weld crack detection system. ACFM can achieve quantitative detection of butt welds in the cladding panel of spent fuel pool, and meet the requirements of high sensitivity in the field.

Crane has been subjected to alternating loads with different characteristics for a long time during service, resulting in a decrease in load-bearing capacity due to structure fatigue. In order to study the impact of load and stress changes on the fatigue life of crane structure during actual work, firstly, a neural network was used to analyze the load spectrum of crane during service and accurately predict the load characteristics, and the stress-time history of the crane during service was analyzed by combining the accurately predicted load spectrum and structural bearing characteristics; secondly, Miner's linear damage accumulation theory and linear elastic fracture mechanics method were used to predict the fatigue life of the key parts of the crane structure; finally, with the fatigue life and structural bearing capacity of the key parts of the crane structure as constraints, an optimization design model considering the load characteristics of the crane during service was established. Intelligent optimization algorithm was used to search for the optimum design variable combination globally to obtain the optimum design parameters of the crane structure that met the design requirements of fatigue life and bearing capacity. The research results showed the feasibility of the method combining the calculation of structural fatigue life with intelligent optimization algorithm in the optimization design of crane structure, providing a new approach for the lightweight design of crane structure.

The wire spring inclination angle is one of the important design parameters for the wire spring hole electrical connector, which has a significant impact on its storage life. Aiming at this problem, the failure mechanism of the wire spring hole electrical connector was analyzed when the wire spring inclination angle changed in the storage environment, and its storage reliability statistical model was established. On this basis, a mathematical model of the storage life of wire spring hole electrical connector varing with the wire spring inclination angle was established. Finally, a constant stress accelerated degradation test scheme was developed and relevant tests were carried out. Through statistical analysis of the test data, the performance degradation model parameter estimates of the wire spring hole electrical connector under different wire spring inclination angles (7o?10o) were obtained, achieving the storage reliability evaluation of electrical connectors. The results showed that the goodness of fit of the functional relationship between storage life and wire spring inclination angle obtained by least square method was as high as 0.968 1, which verified the accuracy of the established model. The research results can provide a theoretical basis and reference for the reliability growth design of wire spring hole electrical connectors in the future.